When comparing Polynote vs StackEdit, the Slant community recommends StackEdit for most people. In the question“What is the best cross-platform note taking app?”StackEdit is ranked 18th while Polynote is ranked 36th. The most important reason people chose StackEdit is:

StackEdit works directly from the browser, there's no need to install additional software as long as you have a web browser installed on your computer.

Pros

Pro

Real-time collaborative

Pro

Minimal interface

The application is simple and fast. Can create, share and organize notes and notebooks on the same page.

Pro

No need to install additional software

StackEdit works directly from the browser, there's no need to install additional software as long as you have a web browser installed on your computer.

Pro

Works online and offline

StackEdit works within your browser. You need internet access to connect to the website, but once it's loaded, the site does not require an internet connection - you will be able to edit and save files locally. Additionally, you can use Fluid to turn it into a native desktop application.

Pro

Syncs via Dropbox and Drive

Files can be synchronized through Dropbox and Drive.

Pro

Real-time preview

The preview shows in a collapsible pane on the right hand side.

Pro

Multiple export options

Can export to .txt, .html and .pdf.

Pro

Supports various Markdown flavors

Supports standard Markdown and Markdown Extra.

Pro

Instant publishing

StackEdit allows pushing a document directly to a list of publishing or file storage platforms or any SSH server.

Pro

Simple workflow

It is very easy to toggle between the preview and the editing windows. The black makes it a very focused writing environment. Of course it's possible to change that if needed.

Pro

Great when in full-screen

Cons

Con

No free tier

Plynote has a 15-day free trial after which it requires a 20$/user/year subscription.

Con

Saves files in browser's local storage

Local storage is limited and if the browser crashes the text can be lost.

Con

Cannot be accessed while being offline

Even though the editor itself works offline, you need internet access to open the website and the editor.

Con

Lacks a good integrated spell checker

Uses the built-in browser spell checker which may not be as good as spell checkers other editors have. Depending on the browser, of course.

Con

Publishing to GitHub requires giving write access to repos

In order to publish documents to GitHub, StackEdit requires writing access to your repos, something which many people may not be comfortable with.